RE: SDCARD in SD Card Mode, SPI mode and Maximum speeds?

Carl Richard — Tue, 20 Jul 2021 14:49:19 GMT

Hello, Owain!

Apologies for the somewhat late answer here. I will try to answer your questions clearly:

- You are indeed limited to 8MHz speed on the normal SPI peripherals. However, the nRF5340 does boast a fourth SPI peripheral with support of 32MHz speeds.
- From what I can see this is true. Non of our devices supports 4-bit SD Card interfacing, so I believe this would be difficult to utilize anyway.
- I think you can find better answers for this elsewhere, but based on what I could find the speed in SPI mode maxes out at about 40 MHZ.
- Our QSPI peripheral only supports NOR type flash.

I think your best option for higher speeds if you want to use SDCards is to use the nRF5340 high speed SPI.

Best regards,
Carl Richard